Your questions are specific enough that you should call Ralph at Atmasphere. He's a nice guy and will not mind helping you. Plus, there is no question as to the reliability of the answers you will get.
Albert makes a good suggestion. Ralph was extremely helpful to me when I was considering buying a used MA-2. There was never any question about my buying used versus new, he was more than willing to answer all my questions even though my decision to buy used would in no way benefit him. You can also reach him via e-mail from his website: http://www.atma-sphere.com
I also have second-hand testimony as to RK's willingness to assist in advising on used Atma-Sphere purchases. Don't expect this kind of magnanimous treatment from say, Luke Manley at VTL, or Richard Vandersteen. I wish more manufacturers understood the worth to them of helping to keep their gear's resale value and desireability high, instead of short-sightedly disparaging those whose second-hand purchases ultimately help fuel a robust primary market.